The present invention refers to a mixing and kneading apparatus, comprising a housing delimiting a work space, a working member located in the interior of the housing, a drive assembly for driving the working member to a rotating and to a reciprocating movement, and a sealing assembly located between the housing and the working member. Further, the invention also refers to a sealing assembly for sealing a working member located in a housing and driven to a rotating and reciprocating movement, whereby the sealing assembly is located between the housing and the working member.
Mixing and kneading apparatuses of the kind referred to herein are used, for example, for processing highly viscous masses, for homogenizing and plastifying plastic materials and for admixing fillers and reinforcing additives to such masses.
In order to provide for mixing and processing these materials as homogeneously as possible, such mixing and kneading apparatuses comprise a working member, e.g. a shaft member provided with mixing and kneading vanes, that is driven not only to a rotating movement, but simultaneously to a reciprocating movement as well. One difficulty in using a rotating and simultaneously reciprocating working member consists in the fact that it is very difficult to seal that working member vis-a-vis the housing in such a way that a perfect seal is maintained over an extended period of time. Moreover, caused by the two motions of the working member superimposed to each other, a wobbling motion of the working member can result what renders a reliable sealing even more difficult to achieve.